edited presentation supramolecular chemistry in fibre...

Supramolecular chemistry in fibre processing: New

opportunities for functional biomaterials

10.12.2012 Laboratory of Fiber and Cellulose Technology, Porthansgatan 3-5, 20500 Åbo, FINLAND

1

Åbo Akademi University Laboratory of Fibre and Cellulose Technology

Dep of Chemical Engineering

Pedro Fardim, Carl Lange, Beatriz Vega, Thomas Heinze

Edited presentation

[email protected]

Our core competence in Biomass Engineering

Laboratory of Fibre and Cellulose Technology (FCT)

www.abo.fi/fct

Topochemistry

Eco-materials Nanotechnology

Bioenergy

Fibres Sustainable processes

Chemistry in 3D Topology Surface chemistry

Supramolecular chemistry Self-assembly Nanoanalysis

Composites Bioplastics Biochemicals Packaging Paper

Pretreatment Fractionation Functionalisation Shaping

Biofuels Bioconversion

Biomaterials Smart materials Personal care

Supramolecular chemistry

§  Supramolecular Chemistry is all about interactions between molecules: how they can recognise each other, assemble and function on a molecular scale.


3


4

Lehn, J-M., Nobel Lecture, 1987

5

Intramolecular Forces

§  Forces binding atoms in a molecule are due to chemical bonding (intramolecular), e.g.: – Metallic bond (inner electron) –  Ionic bond (inner electron) – Covalent bond (outer electron) – Coordination bond (outer electron)

6

Intermolecular forces §  Forces holding molecules together

(intermolecular) – Dipole-dipole interactions – Hydrogen bonds – Dispersion bonds (also called van der Waals or

London)

The intermolecular forces determines the physical properties of substances and materials, e.g. boiling point (bp), melting point (mp), solubility, surface tension, adhesion, etc.

7

Bond energies

Chemical forces Bond energy (kJ/mol) Metallic bonds 2100 Ionic bonds 630 Covalent bonds 460 Coordination bonds 210 Hydrogen bonds 21 Dipole-Dipole 4 Dispersion 4

Supramolecular assemblies in fibre processing

1. Cellulose assembly in pulping


8

AGGREGATION OF NANOFIBRILS DURING PULPING

§  Cellulose nanofibrils (2-4 nm) form aggregates of 16-30 nm during pulping (Wickholm, 2001; Hult 2001)

§  Co-crystallization or coalescence of cellulose crystals during pulping (Newman, 1994; Ioelovich, 1989)

Other effects Temperature as dominating factor

for increase of cellulose crystallinity (Attala, 1978; Isogai et al 1991)

CHEMICAL DEGRADATION IN PULPING

12 14 16 18 20 22 2410

12

14

16

18

20

22

24

26

28

30

32

34

36

38

40

Active alkali in pulping (% Na2O)

Iso Brightness (% ISO)

Lignin content x10 (%)

Kappa number

Lignin

12 14 16 18 20 22 240

10

20

30

40

1000

1200

1400

1600

1800


Cellulose retention (%)

Degree of Polymerization

Cellulose

XYLAN DEGRADATION

12 14 16 18 20 22 240

2

6

8

10

Active alkali (% Na2O)

Xylan retention (%)

Uronic acid retention (%)

X-ray Diffraction

0 10 12 14 16 18 20 22 2456

70

72

74

76

78

80


Wood

Cristallinity index (Cr)

? 17

16

0 10 20 30 40 50

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Line

ar in

tens

ity (c

ount

s pe

r sec

)

Diffraction angle 2θ (degrees)

(101)

(002)(020)

(110)

CPMAS 13C NMR

10 12 14 16 18 20 22 24 2644

46

48

50

52

54

56Xc

Cel

lulo

se c

rista

llini

ty (

%)

Active alkali (% Na2O)

Transition point

NIR and PCA

PC1 (93,3%)

PC2

(3

,70

%)

HF12A

HF14A

HF15A

HF16A

HF17A

HF18AHF20A

HF22A

HF24A

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4

Transition point detected by PC1

PC1 H2O

Ph-OH

Work of adhesion

15 20 25 30

20

40

60

80

100

120

140

Wap-AB

Wap-LW

Wap

mJm

-2

Active alkali in pulping (% NaOH)

Fardim, Durán (2005), J. Braz. Chem. Soc. 16 (5) 915

More H-bonds

Surface Energy

15 20 25 30 35

22

24

26

28

30

32

34

36S

urfa

ce e

nerg

y (m

Jm-2)

Active alkali in pulping (% NaOH)

Lignin removal increases γ

A Hypothesis is put forward

§  Different molecular self-assemblies are formed during kraft pulping of eucalyptus

§  The self-assembly mechanism is driven by H-bonds and increase in γ due to removal of lignin

§  The adhesion forces during cocrystallisation cause increase of order in nanofibrills

0 10 12 14 16 18 20 22 2456

70

72

74

76

78

80


Wood

Cristallinity index (Cr)

M1

M2

Aggregation of nanofibrils ΔGagg= -T[ΔSagg] : entropy driven

Molecular self-assembly (ΔGinteraction dominates the process, not ΔSagg)

New insigths in Pulping

§  Control of fibre-water interactions §  Tailoring of crystallinity of fibres §  Effects on fibre wall compressibility/

mechanical properties §  New route to obtain nanocellulose


2. Xylan assembly in oxygen bleaching


21

Notice

§  This part has unpublished data which was removed

§  Data will be available after publication


22


23

Contact angle and surface energy

Contact angles (CA) of a ethylene glycol droplet on a oxygen bleached pine fibre with 2 % hot water extracted xylan added. sample: QX-1-47-T)

Bleached pine fibre γSV γSVLW γSVAB γSVA γSVB

QX-1-47-T (GM) 47.4 29.9 17.5

QX-1-47-T (vOCG) 36.0 29.9 6.11 0.3 28.5

Cooperation with Tampere


3. Extractives assembly in low-consistency refining


24

Surface coverage by XPS

Carbohydrates

Lignin

Extractives

R

R

R

Modification of fibre surfaces during LC-refining

New Insights in Refining

§  Modification of fibre surfaces §  Release of xylan and fatty acid salts

from fibre wall to fibre surfaces §  Strategies to benefit of this mechanism:

– Encapsulation of chemical to promote bonding/interactions with paperchemicals

–  Removal of paperchemicals (defoamers/biocides) in papermachine


4. Xylan polyelectrolytes assembly in wet-end


28

Xylan

•  Raw material: birch chips

•  Extraction conditions: 160°C, 10 min, static pressurized hot water

extraction mode

•  Sugar composition: 73% xylose, 3% methyl glucuronic acid

•  Mw = 10728 g/mol

•  DSac = 0.39

•  Soluble in: Water DMSO, and DMF/LiCl

Xylan derivatives (XDs)

CMX-

XS-

XN+

§ Chemical characterization using: §  NMR, SEC, HPLC

Characterization of XDs

CMX-

XS-

XN+

Weight average molar mass (Mw), degree of polymerization (DP) and polydispersity (PDI) of pressurized hot water extracted xylan and xylan derivatives determined by size exclusion chromatography Sample Structure DS MRU

*

[g/mol]

Mw [g/mol] DP DPI

Xylan

0.39 (acetate) 148 10728 72 2.1

XS-‐

0.16 148 16314 110 1.5

CMX-‐

0.50 172 16153 94 2.0

XN+

0.32

200 -‐-‐-‐-‐-‐-‐-‐-‐ 276* 1.7

*MRU, Molar mass of repeating unit

O

OOR

R O

C H 3

OR = H ,

O

OOR

R O

R = H , S O 3Na

O

OOR

R O

R = H , C H2 COO Na

R = H, ,

N(C H3 )3 C l

O

O

OOR

R O

C H 3

O


*

[g/mol]

Mw [g/mol] DP DPI

Xylan

0.39 (acetate) 148 10728 72 2.1

XS-‐

0.16 148 16314 110 1.5

CMX-‐

0.50 172 16153 94 2.0

XN+

0.32

200 -‐-‐-‐-‐-‐-‐-‐-‐ 276* 1.7


O

OOR

R O

C H 3

OR = H ,

O

OOR

R O

R = H , S O 3Na

O

OOR

R O

R = H , C H2 COO Na

R = H, ,

N(C H3 )3 C l

O

O

OOR

R O

C H 3

O


*

[g/mol]

Mw [g/mol] DP DPI

Xylan

0.39 (acetate) 148 10728 72 2.1

XS-‐

0.16 148 16314 110 1.5

CMX-‐

0.50 172 16153 94 2.0

XN+

0.32

200 -‐-‐-‐-‐-‐-‐-‐-‐ 276* 1.7


O

OOR

R O

C H 3

OR = H ,

O

OOR

R O

R = H , S O 3Na

O

OOR

R O

R = H , C H2 COO Na

R = H, ,

N(C H3 )3 C l

O

O

OOR

R O

C H 3

O

vacuum filtration

through glassmicrofibre

filter

polyelectrolyte titration

surface characterization

of pulp

Initial concentration of

XD

Final concentration of

XD

Sorption of XDs on fibre surfaces*

*bleached pine kraft pulp

Sorption of XS- on fibre surfaces

0.000

0.002

0.004

0.006

0.008

0.010

0.000 0.005 0.010 0.015 0.020 0.025 0.030

meqsorbed/100 mg dry pulp

meq free

XS- sorption isotherm

Sorption isotherm showing the amount of XS- per 100 mg of bleached pine Kraft pulp versus “meq free” representing the amount of XS- still in solution after sorption.

Sorption of CMX- on fibre surfaces

0.000

0.002

0.004

0.006

0.008

0.010

0.00 0.01 0.02 0.03 0.04 0.05


meq free

CMX- sorption isotherm

Sorption isotherm showing the amount of CMX- per 100 mg of bleached pine Kraft pulp versus “meq free” representing the amount of CMX- still in solution after sorption.

Sorption of XN+ on fibre surfaces

0.000

0.002

0.004

0.006

0.008

0.010

0.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035


meq free

XN+ sorption isotherm

70 µmol of XN+ / g pulp

Sorption isotherm showing the amount of XN+ per 100 mg of bleached pine Kraft pulp versus “meq free” representing the amount of XN+ still in solution after sorption.

Sorption of XN+ on fibre surfaces

70 µmol XN+/ g pulp

73 µmol SAGs/ g pulp

Surface anionic groups (SAGs) value was determined by using X-ray photoelectron spectroscopy (XPS)

The amount of sorbed XN+ was estimated from the sorption isotherm

Vega et al, Carb. Pol. 89, 3, 1 July 2012, Pages 768–776

Åbo Akademi University - Domkyrkotorget 3 - 20500 Åbo 37

Total ion Peaks 58 + 146 0.5 mg/ml XTMAB The surface distribution of the XTMAB polymers on the fibres was quite

homogeneous and the polymer is covering evenly the surface

Sorption experiments using XTMAB, ToF-SIMS imaging

100 µm 100 µm


5. Polysaccharide-nanohybrids assembly


38

The concept in general


39

From colloidal particles… …and pulp fibres…

…to functionalized fibres…

…to product ideas.

flame retardant insulation

composites rethinking pulp

The colloidal particles


40

§  Layered Double Hydroxides (LDH) •  Are formed from divalent and trivalent mixed

metal hydroxides (Mg2+, Zn2+,Al3+, Cu2+, Fe2+/3+ etc) ü  They are versatile!

•  Occurs in nature with a chemical composition of Mg6Al2(CO3)(OH)16 • 4(H2O) and is called the Hydrotalcite ü  Can be synthesized from non toxic chemicals!

•  One of the rare cationic minerals therefore behaving as an anion exchanger ü  Favourable charge with respect to pulp fibres!

The colloidal particles


41

http://webmineral.com/data/Hydrotalcite.shtml

Rethinking pulp


42

0,000 0,005 0,010 0,015 0,020 0,025-0,2

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6 OBA-pulp LDH/OBA pulp

ΨOBAO.D.

A

Leaching of OBA into pulp filtrate•  Optical brightening agents (OBA) are anionic and require retention aids to incorporate them into pulp fibre matrix.

•  LDHs are white particles and they capture anions easily from aqueous solution.

•  Prevents leaching of OBA into effluent thus reducing chemical dosage and effluent contamination


43

Rethinking pulp

under natural light

under UV-light


44

Rethinking pulp

0 3 6 9 12

0

20

40

60

80

100

120

140

dθap

p/dt

SDS (%)

•  Surfactants can be bound to pulp fibre matrix.

•  LDHs are can be used as a platform to impart hydrophobic character to pulp fibres.

•  High contact angles can be achieved!


45

Rethinking pulp

Water is unable to penetrate the fibre matrix

•  Injection moulded to match ISO 527-2 1BA test specimen •  Atactic polypropylene matrix

•  Chosen because it is cheap, widely applicable and hydrophobic.

•  Working temp.: 190 °C (200 rpm, 2 min) •  Injection pressure: 4 bar (40 °C) •  Pulp to matrix ratio: 0.2


46

Composites


47

A B C D E F

A)  PP matrix B)  PP + fibres C)  PP + fibres with 10 mM LDH, D)  PP + fibres with 100 mM LDH E)  PP + fibres with 100 mM LDH + 3% SDS F)  PP + fibres with 100 mM LDH + 6% SDS

Composites

BKraft BTMP


48

BTMP E (MPa) σ(YS) (MPa) ε(max) (%)

50 mm /min 5 mm /min 50 mm/min 5 mm/min 50 mm/min 5 mm/min

PP 5.46 24.9 > 300

PP + BTMP 11.3 7.48 39.5 29.6 9.32 20.6

PP-BTMP-LDH (100) 11.8 8.20 35.2 30.5 14.4 15.6

PP-BTMP-LDH (100) + 3% SDS 10.7 7.85 30.8 28.3 17.5 20.3

Composites

Standard deviations are approximately 10% in each value

Under a relatively fast (50 mm/min) and slow (5 mm/min) deformation rate showing the elastic and viscous behaviour of the composite respectively


49

BKraft E (MPa) σ(YS) (MPa) ε(max) (%)

PP 5.46 24.9 > 300

PP-Bkraft 7.66 35.2 17.8

PP-BKraft-LDH (10) 7.01 30.1 27.1

PP-BKraft-LDH (100) 6.52 27.3 28.7

PP-BKraft-LDH (100) + 3% SDS 7.77 30.1 18.9

Standard deviations are approximately 10% in each value

Composites Relatively slow (5 mm/min) deformation rate showing the viscous behaviour of the composite

§  Supramolecular chemistry in fibre processing: –  Hydrogen bonds –  Hydrophobic interactions –  Electrostatic forces –  New multifunctionalisation strategies for fibres

§  Supramolecular assemblies: –  New pulp fibres –  Functional polysaccharides in fibre lines (O

bleaching) and wet end –  Bionanohybrids as functional agents for biofibres –  New bioproducts for different value chains 10.12.2012 Laboratory of Fiber and Cellulose Technology, Porthansgatan 3-5,

20500 Åbo, FINLAND 50

Conclusions

References §  Hybrid Clay Functionalized Biofibres for Composite Applications. C Lange, F Touaiti, P

Fardim - Composites Part B: Engineering, 2012http://dx.doi.org/10.1016/j.compositesb.2012.10.032

§  Hydrophobisation of mechanical pulp fibres with sodium dodecyl sulphate functionalised layered double hydroxide particles. C Lange, T Lundin, P Fardim - Holzforschung, 2012 DOI: 10.1515/hf.2011.168

§  Studies on the fibre surfaces modified with xylan polyelectrolytes. B Vega, K Petzold-Welcke, P Fardim, T Heinze - Carbohydrate Polymers, 2012http://dx.doi.org/10.1016/j.carbpol.2012.04.006

§  Molecular assembly in kraft pulping of Eucalyptus. P. Fardim, N. Duran. O Papel 2007, 68, 8, 98-108 . http://www.revistaopapel.org.br/noticia-anexos1311965922_9fed06c715ac8765dcec040e4da8bed6_781788484.pdf

§  Modification of fibre surfaces during pulping and refining as analysed by SEM, XPS and ToF-SIMS. P Fardim, N Durán - Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2003 http://dx.doi.org/10.1016/S0927-7757(03)00149-3

§  Extractives on fiber surfaces investigated by XPS, ToF-SIMS and AFM P Fardim, J Gustafsson, S von Schoultz, J Peltonen… - Colloids and Surfaces A: Physicochemical and …, 2005http://dx.doi.org/10.1016/j.colsurfa.2004.12.027


51

Acknowledgements

§  Prof. Philip Turner and Zurine Hernandez §  Tekes §  Academy of Finland §  Metsafiber, UPM, StoraEnso, Kemira,

Danisco, ViscoTeepack §  Friedrich Schiller University of Jena,

Germany §  University of Sao Paulo (USP), Brazil


52

edited presentation supramolecular chemistry in fibre...

Documents